Video: Mikel San Jose's incredible long range goal against Barcelona
Bilbao, who came up as second best in the Copa Del Rey final few months back, stunned the visitors as veteran striker Artiz Aduriz bagged a second-half hat-trick to gain a massive advantage over their La Liga counterparts in the two-legged competition.
Spanish Supercopa: Athletic Bilbao 4-0 FC Barcelona - Player ratings
Barcelona surrendered a three-goal lead in the UEFA Super Cup against Sevilla in midweek and despite winning the game that time around, their defensive frailties were put under the magnifying glass again against Basque side Athletic Bilbao.
Spain look to continue with generational change in match against Netherlands
Del Bosque will continue with his rejuvenation of the side in Holland. David De Gea is likely to play in goal as he continues to play international minutes and line himself up as the successor to Iker Casillas.